The next full trailer for Marvel's Avengers: Age of Ultron is set to air tomorrow, but before that hits our screens, Entertainment Tonight have given us an early preview of the next installment into the Avengers saga along with a few behind-the-scenes words from some of the movie's stars. The video shows some brand new scenes, the most interesting of which sees the brother/sister duo of Quicksilver and Scarlet Witch taking on Captain America and Black Widow.

Just in case you missed it, here's a grainy gif of the Maximoffs going to work.

Just like yesterday's Avengers: Age of Ultron teaser, ET's footage also hints at a possible romance between Bruce Banner and Black Widow, but all the cast members revealed it's been painfully hard not to give away any of Marvel's closely guarded plot secrets, so it looks like it's unlikely we'll get any confirmation on plotlines until the movie is released.

One thing does seem for sure, though. You can expect the majority of this footage to appear in Thursday's second trailer, which airs during ABC's American Crime at 10/9c.

In the meantime, Marvel seems content to tease its fans by releasing a string of character posters for the movie. We've already had posters for Captain America, Hawkeye, Black Widow, Thor, Nick Fury", Iron Man and Hulk, which means we are just waiting for the last few Avengers and, of course, the movie's titular character, Ultron.

Marvel's Age of Ultron hits theaters May 1st and you can check out the official synopsis for the movie, below.

Marvel Studios presents Avengers: Age of Ultron, the epic follow-up to the biggest Super Hero movie of all time. When Tony Stark tries to jumpstart a dormant peacekeeping program, things go awry and Earth's Mightiest Heroes, including Iron Man, Captain America, Thor, The Incredible Hulk, Black Widow and Hawkeye, are put to the ultimate test as the fate of the planet hangs in the balance. As the villainous Ultron emerges, it is up to The Avengers to stop him from enacting his terrible plans, and soon uneasy alliances and unexpected action pave the way for an epic and unique global adventure.